Evolution of the Hongzhen metamorphic core complex: Evidence for Early Cretaceous extension in the eastern Yangtze craton, eastern China

Research Article| March 01, 2010 Evolution of the Hongzhen metamorphic core complex: Evidence for Early Cretaceous extension in the eastern Yangtze craton, eastern China Guang Zhu; Guang Zhu † 1School of Resource and Environmental Engineering, Hefei University of Technology, Hefei 230009, China †E-mail: zhuguang59@hotmail.com Search for other works by this author on: GSW Google Scholar Cheng-Long Xie; Cheng-Long Xie 1School of Resource and Environmental Engineering, Hefei University of Technology, Hefei 230009, China Search for other works by this author on: GSW Google Scholar Wen Chen; Wen Chen 2Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China Search for other works by this author on: GSW Google Scholar Bi-Wei Xiang; Bi-Wei Xiang 1School of Resource and Environmental Engineering, Hefei University of Technology, Hefei 230009, China Search for other works by this author on: GSW Google Scholar Zhao-Qi Hu Zhao-Qi Hu 1School of Resource and Environmental Engineering, Hefei University of Technology, Hefei 230009, China Search for other works by this author on: GSW Google Scholar GSA Bulletin (2010) 122 (3-4): 506–516. https://doi.org/10.1130/B30028.1 Article history received: 09 Feb 2009 rev-recd: 05 May 2009 accepted: 06 May 2009 first online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Guang Zhu, Cheng-Long Xie, Wen Chen, Bi-Wei Xiang, Zhao-Qi Hu; Evolution of the Hongzhen metamorphic core complex: Evidence for Early Cretaceous extension in the eastern Yangtze craton, eastern China. GSA Bulletin 2010;; 122 (3-4): 506–516. doi: https://doi.org/10.1130/B30028.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract We conducted structural and geochronological studies on the Hongzhen metamorphic core complex in the eastern Yangtze craton. The hanging wall of the Hongzhen metamorphic core complex consists of Neoproterozoic to Permian unmetamorphosed strata, which were folded during NW-SE shortening in the Middle Triassic, and Cretaceous terrestrial basins. The exposed Paleoproterozoic Dongling Complex in the footwall is widely overprinted by a detachment ductile shear zone, which has consistent SW-plunging mineral elongation lineations and top-to-the-SW shear indicators. Analysis of the mesostructures, microstructures, and quartz C-axis fabrics indicates that they formed within a low-angled, SW-dipping, extensional shear zone at midcrustal levels. Four muscovite grains separated from mylonites within the shear zone yielded 40Ar/39Ar plateau ages ranging from 128.5 ± 1.0 Ma to 126.1 ± 1.1 Ma. They are interpreted as cooling ages of the shear zone associated with the Hongzhen metamorphic core complex. We propose that the Hongzhen metamorphic core complex was initiated as a midcrustal, low-angle extensional shear zone with top-to-the-SW shear sense at ca. 145 Ma, and the shear zone was then warped and uplifted by the emplacement of the Hongzhen granite at 122 Ma. Brittle normal faulting and basin rifting in the hanging wall also developed during the formation of the Hongzhen metamorphic core complex, but these processes continued until the Late Cretaceous. This study of the Hongzhen metamorphic core complex demonstrates that the eastern Yangtze craton was also involved in the Early Cretaceous extension widely occurring in the eastern China continent. A NE-SW extensional direction during the Early Cretaceous is indicated by the Hongzhen metamorphic core complex. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.